倒Y型四能级量子系统中亚光速和超光速传播现象的转换研究

研究了探测场、耦合场和驱动场三场作用下倒Y型四能级量子系统的光学特性,利用数值模拟的方法探讨了外加相干驱动场的拉比频率和失谐量变化时系统对探测光场吸收特性的影响. 通过绘制三维立体图,发现了探测光场的群速度在电磁诱导透明窗口处的变化规律,并且选择合适的驱动场拉比频率和失谐量,可以在理论上实现亚光速和真空光速以及超光速传播之间的转换. 关键词： 倒Y型四能级 群速度 超光速传播 亚光速传播

The conversion between subluminal and superluminal light propagation phenomena in an inverted Y-type four-level quantum system

We have studied the light propagation properties in an inverted Y-type four-level quantum system coupled with probe, couple and driving fields. Using the numerical simulation method, we investigate the absorption properties of the probe light field when the Rabi frequency and detuning of the driving field are changed. From the three-dimensional graphics, we find the variations of the probe group velocity at the electromagnetically induced transparency windows. Farthermore, we theoretically obtain the conversion among subluminal, vacuum and superluminal light propagation by adjusting the Rabi frequency and detuning of the external driving field properly.